1641 PTO and AMP Light

[cewing]

Hello ... new here and tried to search for this problem but could not find anything close.

I have a 1641 which when the PTO is engaged, the AMP Light comes on and if you run the mower the battery will eventually be drained.

Does anyone know the method for electrically testing the PTO? Current and Voltage.

Thanks

 

[rbedell]

Chris E:

First, Welcome to the Forum.

The 1641, had two different types of Warner PTO Clutches in them, depending on the serial number.

Here is a test procedure, that would work for either:

Next, I would suggest that you inspect your wiring, to see if there is any discoloration, bubbling, or burnt wires and/or connectors. That the PTO Clutch has a minimum of 12.0 VDC going to it. Here is a schematic for your PTO Circuit:

 

[cewing]

Thanks!! That's exactly what I was looking for.

 

[cewing]

Roland,

Well I checked out the PTO and the resistance, current draw and voltage were right on, so the good news I don't have to buy a ~$300 part. So, now the question is why is the Amp Light on. I didn't go into much research on your lower diagram and I am trying to figure out where any major current draw might be. I am leaning on thinking its the charging system. Is this the next step???

Thanks again!

 

[rbedell]

Charles E:

YUP...you are on the right track.

Let me say, I know very little about the B&S Motors.
BUT...a Charging Circuit in principal is the same as with a Kohler.

With the Motor at full throttle or 3600 RPM's, the output voltage should be 30VAC at a minimum to the Regulator/Rectifier. The Output of the Regulator/Rectifier should be 12.0 to 14.7 VDC Maximum. I assume, since I have not seen one of these, that the R/R has a metal case, and has to be grounded. Make sure there is zero ohms from the R/R case to the negative battery terminal.

See this diagram from the B&S Service Manual...

Let us know what you find after testing...

 

[dcurrin]

Charles,

Welcome to the neighborhood...

In your original post you did not state that it was running.

If you do not engage the PTO is the result the same only that it takes more time?

If you have headlights turn them on to see if you get the same problem.

If both answers end the same. IE dead battery then there is a charging system problem.

If not then the circuit (ie PTO) that causes the dead battery has a problem.

3 or 4 amp draw on 16 amp supply should not cause a dead battery.

Hopefully your battery is in good condition. As are all wiring connections including grounds.

Dudley

 

[cewing]

Dudley,

Thanks for the welcome:

The light comes on whether the motor is running or not when the PTO is engaged and it comes on instantainiously.

Unfortunately the headlight are not working (I am just now taking over maintenance on this tractor). I may fix them later, but they are not needed now.

The battery seems strong since with the drought here, the lawn hasn't been mowed in a couple of weeks and while I have been testing it, leaving it for a week, the engine starts right up.

Roland, I tested out the charging/regulating circuits and with the motor at full throttle the output voltage of the alternator was 28.4 VAC. The Output of the Regulator/Rectifier 2.9 VDC. The resistance was ~0.2 ohms from the R/R case to the negative battery terminal.

So ...... it looks like a bad R/R. I was shocked when I saw ~3Vs ... hmmm

I ordered a R/R from Pat's Small Engine Plus ... http://www.psep.biz/store/briggs_charging_parts.htm ~$75 w/shipping

Thanks again!

 

[rbedell]

Charles E:

YUP....2.9 VDC ain't quite enough. Glad you found the issue.

Just image, running the PTO and your lights, you probably would have killed the motor....

 

[dcurrin]

Charles,

Post the results with the new regulator, too.

Good Troubleshooting.

So many people dont take the time to check all the details that add up to the correct answer.

Cheers
Dudley